Gyre Engineer

A mana dork that taps for two pips is a rare license, and the price here is a fragile 1/1 body plus an output locked to green and blue together: the ability never hands you a single pip on its own, so it accelerates Simic and nothing else. That restriction defines the card. As a fair accelerant it is unremarkable, a three-mana investment that dies to any removal and produces mana you could have gotten more cheaply. The interest is entirely in the doubled tap. Any effect that untaps a creature or scales off the mana it produces attaches a green-blue engine to it, and the card's history is largely a catalogue of what people have chained off that engine once the fixing turned into infinite-mana potential: untap loops, cost-reducers, activated abilities hungry for colored mana. The two-in-one activation is what pulls it out of the ramp category and into the combo one. It rewards being the first link in a chain rather than a rung on a curve, which is why its most durable identity is as a piece in a build looking to break the loop wide open, not as a body meant to survive a turn cycle and add up over time.